A series of neurophysiological studies will be made of the central and peripheral mechanisms of the larynx. The primate Macacus Rhesus will be employed as the experimental animal to determine cortical and subcortical areas in the motor control of the intrinsic laryngeal muscles. The cortical and subcortical areas of the primate brain will be explored and plotted, with confirmation of areas made by recording the action potential from the recurrent laryngeal nerve and by axonal and terminal degeneration studies. In addition, measurements will be made of the mechanical properties of the intrinsic laryngeal muscles via central electrical stimulation. Findings will be correlated to previously collected data from studies of peripheral and pathological entities of the laryngeal organ.